Fossils of oldest known snakes unearthed

Julius T. Csotonyi

Fossils of oldest known snakes unearthed

Four new species of ancient snakes, including one that lived in what is now southern England, push back the known kin of today’s slitherers almost 70 million years earlier than thought. The species—one from the United States, two from England, and one from Portugal—were identified from new analyses of fragmentary fossils collected decades ago but then consigned to museum drawers. These fossils have been dated to between 143 million and 167 million years ago; previously, the oldest known snake fossils were about 100 million years old. Because the sediments that entombed the fossils were deposited in distinctly different environments, it’s likely the creatures (artist’s concept of one of the species shown above) inhabited different habitats, the researchers say. The fossils, including teeth and skull or jaw fragments from all four species but vertebrae from only two, show all the hallmarks of snakes, especially in the creatures’ heads, the researchers report online today in Nature Communications. The fossils are so fragmentary that it’s not clear how long these snakes were or how they were shaped, the researchers note. In fact, some of the vertebrae from one of the new species suggest that that creature had rear limbs. (Leglessness doth not a snake make: There are, in fact, legless lizards today.) The wide distribution of the four new species, as well as their presumed ecological diversity, hints that the earliest snakes probably evolved between 220 million and 240 million years ago (about the time that the supercontinent Pangaea was breaking up), if not earlier.